If you think the UK is socialist then you are clearly delusional. If that hurts your feelings, so be it. It's simply a fact as the UK is clearly not socialist.
Just because it's expensive to currently govern society, doesn't mean we should abandon the governance of society or hand over over direct control to those with the most wealth. If it cost 70% of GDP to sufficiently support society then anything less than that would see society deteriorate.
My argument is that people shouldn't pay any taxes anyway. Businesses should pay those taxes directly instead of palming them off to employees and customers. Those that earn the most from every $1 spent should have the highest tax rates.
Why are you against that? Why should those making money from the least effort have lower or similar tax rates to those who making money from the most effort? If you have two workers the same age doing the exact same job and one is extremely lazy and the other is a proper hard worker, would you say they should be paid the same amount?
Edit: In response toy your edit.
It's easy to see how "efficient" and "useful" all that tax money is spent and how great that centrally-planned system of one NHS (oh, that's not socialist??), subsidised council housing (oh, that's not socialist??), £60m per day to those un-accountable technocrats in that un-elected soviet over in Brussels (oh, that's not socialist??) really works.
Yes, both those things are very efficient and useful. For example, look how much the UK spends on healthcare per person compared to the US. The NHS is absurdly more efficient despite the Tories efforts to get rid of it. As for social housing, just look at what's happened in the UK since Thatcher sold off social housing and never replaced it. Now people can't afford to buy homes and rent prices are getting out of hand. More social housing is precisely what the UK needs right now. That doesn't make them socialist though.
Socialism is about the relationship to the means of production, not health care, housing or welfare benefits. Under socialism, workers control the means of production and get a fair share of the profits dependant upon the amount and type of labour they perform.
A good example of socialism would be mining bitcoin at a pool. All the workers get a fair share of the rewards proportional to the amount of work they do. Some workers do more work than others and therefore get a greater share than others. Imagine if it was based on capitalist redistribution, the pool owner would keep most of the rewards for themselves.